Gripping stuff

Here are those four categories of summer tyre, then: touring (for example the Michelin Primacy, Continental EcoContact or Pirelli Cinturato C3), ultra-high performance or UHP (Michelin Pilot Sport 5, Continental Premium Contact 7), ultra-ultra-high performance or UUHP (Michelin Pilot Sport 4S/S5, Continental Sport Contact 7, Pirelli P Zero PZ5) and track/competition tyres (Michelin Pilot Sport Cup 2 and Cup 2R, Pirelli P Zero Trofeo R and Trofeo RS). Broadly speaking, each of the premium brands has a tyre for each category, each with its own individual strengths and weaknesses relative to their rivals.

Should you put touring or UHP tyres on your hybrid VW Golf? UHP, UUHP or track tyres on your Porsche 911? It’s a confusing world, and we haven’t even mentioned the other grenade rolling gently in the direction of your decision making: manufacturer specific versions of each of these various options. N rated for Porsche, MO for Mercedes, star marked for BMW and so on. Will that grenade blow your vehicle’s dynamics to bits if you don’t fit the pricey OE version to your car?

To have any hope of understanding this kaleidoscope of confusion we have to turn to the industry standard radar chart. Because once we’re up at the premium level, engineering-in the tyre attributes you want is frequently a zero sum game. Those beautifully crafted sipes which clear standing water and give tenacious wet weather handling dramatically compromise dry road braking. That compound offering super low rolling resistance increases economy, but means you’re on ice skates as soon as you press on. Deep, aggressive groove patterns designed to reduce aquaplaning create more road noise, increase heat and accelerate wear. In fact, there are so many attributes that need to be considered in the engineering of a high-quality summer tyre it’s going to take a whole paragraph to list them all.

So in no particular order: dry handling, dry braking, wet handling, wet braking, straight aquaplaning, curved aquaplaning, steering precision and feedback, cornering stability, on limit behaviour (wet and dry), sub limit behaviour (wet and dry), rolling resistance, noise (external and internal), ride harshness/comfort, vibration dampening, wear characteristics, puncture resistance, sidewall durability, weight optimisation, material sustainability, and cost to produce. And, increasingly, emissions.

If you put each of these attributes at the point of a star, then we can draw a spider’s web between them. Whilst the area inside our chart will reliably increase as we ascend from budget to mid-range to premium tyres, once we’re at the top of this pyramid we have to choose which compromises we wish to bear. Pulling our star points higher in one direction will inevitably pull them lower somewhere else. And this is where the premium brands each have a distinct identity: the engineers prioritising certain attributes they know their customers value.

Buy a Michelin and you know you’re getting best in class wear, minimised environmental impact and smooth, progressive handling. Choose a Continental and you’re prioritising steering feel, wet grip and braking. With a Pirelli you’ll need a new set five minutes after leaving the tyre shop, but you’ll get delicious dry grip and handling before you have to do a U-turn to go back and get the next set fitted. Yes, I exaggerate for effect, but you understand the point I’m trying to make.

So how about those OE specific versions, which major brands go to great lengths to develop with the tyre manufacturer? Are they automatically the gold standard for what you should fit to your premium motor car? Unfortunately the answer is not simple. In a perfect world the tyre manufacturers would provide us with a radar chart for the N, MO or star rated effort so we can compare it to the standard aftermarket version of the same tyre, and choose which fits our needs better.

But for some inexplicable reason the precise performance attributes of these OE specific tyres are an arcane mystery. Neither car makers nor their tyre partners ever see fit to publish the data or discuss in any detail what was involved in their development.

However there are a couple of generalisations we can make about the way the attributes are tweaked. OEMs will sacrifice tyre life to improve rolling resistance, thus reducing CO emissions, improving tax bands and thus sales. After all, they don’t care if you need to replace the tyres after 5000 miles. Then there may be adjustments to the noise and comfort characteristics – along with tweaks to the compound to help the handling balance, especially in cars with unusual and specific weight distributions, like a 911.

It’s a running debate on Porsche owners forums about whether you should fit N rated tyres or not. My personal opinion is that if you’ve got a modern car (from whatever manufacturer) then OE specific variants might be worth considering. But if the car is more than 10 years old, don’t even think about it. Why? Progress is relentless in the world of tyre development, so fitting the N rated tyres for a noughties era Porsche – a Michelin Pilot Sport 2 – involves choosing a tyre that is fully three generations old. Whatever the advantages that development might have had at the time are now easily outweighed by two decades of progress.

The scale of that progress was recently demonstrated by Jörg Bergmeister blatting a Porsche Carrera GT around the Nordschleife. In December 2024 he clocked a remarkable 7min 12sec, smashing Walter Röhrl’s 2004 best of 7min 28sec. The only difference – modern Cup 2 tyres. If anything, this achievement under-represents the onslaught of progress, as dry grip is one of the attributes that has improved least over the last two decades.

The advances in wet grip and braking are truly mind blowing – for example, up to 20 per cent improvements in wet braking in a single generation (Continental Premium Contact 6 versus previous gen Michelin e-Primacy). Across, say, three generations those improvements are compounded. You’d likely find the difference in the Carrera GT’s wet Nürburgring lap time (if anyone was foolish enough to attempt such a thing) between 2004 and 2024 would be well over a minute.

Whilst we’re on the subject of age, how old is too old for a set of tyres? Frustratingly for your bank balance, less than you think. The oxidative breakdown of rubber compounds hardens the tyre over time, a process that is accelerated by heat and UV exposure. The ballpark consensus from the published research seems to be a reduction in fundamental grip of 15-20 per cent by the tyre’s sixth birthday. Fancy 15-20 per cent longer stopping distances, or a similar reduction in grip when taking emergency action? Me neither.

So when I find myself noodling over a Ferrari 360 on an online auction website (for which Messrs Frankel and Prosser are entirely responsible, legitimising such financial recklessness with the recent ‘buying your first Ferrari’ podcast) and discover that the tyres on it date from 2015, I immediately close the tab and wipe my brow. A lucky escape. If the owner hasn’t stumped up for new tyres in a decade, then firstly, a plague upon all their houses, and secondly, what else has he or she deferred maintenance on?

But I digress. I promised you some grisly details on just how diabolical budget tyres really are. Clearly, they’re atrocious in any metric you care to measure, from dry braking (consider 40 metres instead of 34 metres to stop from 60mph), to wet handling (a 99 second lap versus an 86 second lap), but where they really demonstrate their criminal intentions is in wet braking.

Let’s take two separate tests, looking at all-season and summer tyres (for which I have to doff my cap to Jonathan Benson and his all-conquering Tyre Reviews research. Our first solid performer is the Bridgestone Turanza All Season 6, which pulled up on the wet surface from 50mph in 33.2m. The Fronway Fronwing AS (yes, really) took 48.7m. I’ll save you the maths – that’s a disastrous 15.5m, or 47 per cent further. For fans of leather on willow, that’s over three-quarters of the length of a cricket pitch. Yes really again.

But it gets even worse with the summer tyres. The Continental Premium Contact 6 (itself now a previous generation tyre) stopped on the wet surface from 50mph in 29.6m. The budget option, the Doublecoin DC99 took, wait for it… 51m. And that, dear friends, is more than the length of said pitch. At the point where the Continental stopped, the Doublecoin ploughed past, still doing 32.3mph. I don’t know if you’ve ever gone into the back of someone at over 30mph, but if you haven’t, just ask Isack Hadjar. Turns out it makes quite a mess. And of course, this simple test doesn’t quantify the lack of stability under braking, cornering, accelerating or any other vehicle movement you care to mention.

And so with these infernal warnings of fire and brimstone I hereby endeth my sermon, once more deferring to Forrest’s surely spanner-curious mother. ‘Momma says they was my magic shoes. They could take me anywhere.’

And when you think about it, those frequently forgotten black hoops really are your motor’s magic boots – your entire experience of making progress has to go through them, and only them. Every delicately considered input, every single horsepower your engine can muster, and every nuanced grain of feedback the road has to offer up. Yes, budget tyres are cheap and not everyone can afford the best, but when they are all that’s connecting your car to the road, you need to ask whether they represent a true or false economy.

Ultimately, when the idiot pulls out in front of you without looking, will you be glad you decided to save a few quid a corner, or will you give thanks you didn’t and as a result are not about not have an enormous accident that many and maybe even most of your fellow road users could not avoid? Ultimately, it’s all down to priorities, and I know where mine lie.